Ah, how I love closed source and patent issues.

I have a Microsoft Word file which is password-protected and I have my password for this file - how do I open it in Open Office or how to I remove the password protection from command line?

Open Office 3.x tells me that it plainly does not support this password protection due to licence/propriety issues when I try to open the file.

All those nice little tricks with "insert file" instead of opening and saving as html to plainly remove the pw-stuff does not work on this file.

Any suggestions?

I don't think you can do that in openoffice. You'll need to ask someone with an MS Office package installed to remove the password protection for you.